A new technology utilizing peptoid-coated magnetic beads enables for the diagnosis of Alzheimer’s and Parkinson’s.
FREMONT, CA: Lawrence Berkeley National Laboratory researchers have developed peptoid-coated magnetic beads to detect the presence of misfolded proteins in blood samples. Misfolded proteins are found in patients with diseases, including Alzheimer’s and Parkinson’s. To date, it has been difficult to detect these proteins in blood samples, since they exist in minimal numbers and are very similar to their properly folded cousins. The new beads bind to specific misfolded proteins in blood samples, making room for faster and easier diagnosis of misfolded protein-based diseases.
There is no easy or nominally invasive way of testing prion-related proteins. This is a significant research challenge to ensure the donated blood is free from prion contamination.
The researchers’ technique of testing blood samples for misfolded proteins includes synthetic peptides, known as peptoids attached to magnetic beads.
The peptoid beads can detect the misfolded proteins, which, as infectious agents, can significantly affect the domain of prion diseases. These can, however, scan for substantial aggregated proteins that are, among others, disease agents in Parkinson’s and Alzheimer’s.
When both are present in a blood sample, the beads bind to the protein by magnetic coating beads with peptoid that mimics the detected misfolded protein. The product is large aggregates of the proteins. The aggregated, misfolded protein has numerous hooks — various binding sites — which stick to the bead. The healthy, properly folded protein should, however, have a single hook; hence its binding affinity is much less.
Using a magnet, the misfolded proteins may be isolated from the blood sample after being stuck to the perles. After that, test them using an assay for the presence of the misfolded proteins. The method is easy and quick and can transform the treatment and diagnosis of misfolded protein-based diseases.
In addition to detecting asymptomatic carriers of disease, it is possible to program the bead assay quickly and affordably to scan blood and blood products, a skill that is very important in preventing unintended transmission in the event of a new prion disease outbreak.